dl

dl is awkward because the filename format is OS-dependent and because it can complain if the extension is already loaded. This wrapper function fixes that:<?phpfunction load_lib($n, $f = null) {    return extension_loaded($n) or dl(((PHP_SHLIB_SUFFIX === 'dll') ? 'php_' : '') . ($f ? $f : $n) . '.' . PHP_SHLIB_SUFFIX);}?>Examples:<?php// ensure we have SSL and MySQL supportload_lib('openssl');load_lib('mysql');// a rare few extensions have a different filename to their extension name, such as the image (gd) library, so we specify them like this:load_lib('gd', 'gd2');?>

<?phpfunction dl_local( $extensionFile ) {   //make sure that we are ABLE to load libraries   if( !(bool)ini_get( "enable_dl" ) || (bool)ini_get( "safe_mode" ) ) {     die( "dh_local(): Loading extensions is not permitted.\n" );   }     //check to make sure the file exists   if( !file_exists( $extensionFile ) ) {     die( "dl_local(): File '$extensionFile' does not exist.\n" );   }      //check the file permissions   if( !is_executable( $extensionFile ) ) {     die( "dl_local(): File '$extensionFile' is not executable.\n" );   } //we figure out the path $currentDir = getcwd() . "/"; $currentExtPath = ini_get( "extension_dir" ); $subDirs = preg_match_all( "/\//" , $currentExtPath , $matches ); unset( $matches );      //lets make sure we extracted a valid extension path   if( !(bool)$subDirs ) {     die( "dl_local(): Could not determine a valid extension path [extension_dir].\n" );   }  $extPathLastChar = strlen( $currentExtPath ) - 1;    if( $extPathLastChar == strrpos( $currentExtPath , "/" ) ) {     $subDirs--;   } $backDirStr = "";      for( $i = 1; $i <= $subDirs; $i++ ) {     $backDirStr .= "..";       if( $i != $subDirs ) {         $backDirStr .= "/";       }   } //construct the final path to load $finalExtPath = $backDirStr . $currentDir . $extensionFile;    //now we execute dl() to actually load the module     if( !dl( $finalExtPath ) ) {     die();   } //if the module was loaded correctly, we must bow grab the module name $loadedExtensions = get_loaded_extensions(); $thisExtName = $loadedExtensions[ sizeof( $loadedExtensions ) - 1 ];   //lastly, we return the extension name  return $thisExtName;}//end dl_local()?>

Like with eval(), the only correct way to use dl() is to not use it.Test if a function(s) you intend to use are available.If not, complain to the user or implement a workaround.Not to mention dl() issues in a multithreading environment.

If you need to load an extension from the CURRENT local directory because you do not have privelages to place the extension in your servers PHP extensions directory, this function i wrote may be of use to you

<?php
/*
    Function: dl_local()
    Reference: http://us2.php.net/manual/en/function.dl.php
    Author: Brendon Crawford <endofyourself |AT| yahoo>
    Usage: dl_local( "mylib.so" );
    Returns: Extension Name (NOT the extension filename however)
    NOTE:
        This function can be used when you need to load a PHP extension (module,shared object,etc..),
        but you do not have sufficient privelages to place the extension in the proper directory where it can be loaded. This function
        will load the extension from the CURRENT WORKING DIRECTORY only.
        If you need to see which functions are available within a certain extension,
        use "get_extension_funcs()". Documentation for this can be found at
        "http://us2.php.net/manual/en/function.get-extension-funcs.php".
*/

function dl_local( $extensionFile ) {
    //make sure that we are ABLE to load libraries
    if( !(bool)ini_get( "enable_dl" ) || (bool)ini_get( "safe_mode" ) ) {
     die( "dh_local(): Loading extensions is not permitted.\n" );
    }

     //check to make sure the file exists
    if( !file_exists( $extensionFile ) ) {
     die( "dl_local(): File '$extensionFile' does not exist.\n" );
    }
    
    //check the file permissions
    if( !is_executable( $extensionFile ) ) {
     die( "dl_local(): File '$extensionFile' is not executable.\n" );
    }

 //we figure out the path
 $currentDir = getcwd() . "/";
 $currentExtPath = ini_get( "extension_dir" );
 $subDirs = preg_match_all( "/\//" , $currentExtPath , $matches );
 unset( $matches );
 
     //lets make sure we extracted a valid extension path
    if( !(bool)$subDirs ) {
     die( "dl_local(): Could not determine a valid extension path [extension_dir].\n" );
    }
 
 $extPathLastChar = strlen( $currentExtPath ) - 1;
 
    if( $extPathLastChar == strrpos( $currentExtPath , "/" ) ) {
     $subDirs--;
    }

 $backDirStr = ""; 
     for( $i = 1; $i <= $subDirs; $i++ ) {
     $backDirStr .= "..";
        if( $i != $subDirs ) {
         $backDirStr .= "/";
        }
    }

 //construct the final path to load
 $finalExtPath = $backDirStr . $currentDir . $extensionFile;
 
    //now we execute dl() to actually load the module
     if( !dl( $finalExtPath ) ) {
     die();
    }

 //if the module was loaded correctly, we must bow grab the module name
 $loadedExtensions = get_loaded_extensions();
 $thisExtName = $loadedExtensions[ sizeof( $loadedExtensions ) - 1 ];
  
 //lastly, we return the extension name
  return $thisExtName;

}//end dl_local()

?>